Toxic fruits hold the key to reproductive success
In the course of evolution, animals have become adapted to certain food sources, sometimes even to plants or to fruits that are actually toxic. The driving forces behind such adaptive mechanisms are often unknown. Scientists at the Max Planck Institute for Chemical Ecology in Jena, Germany, have now discovered why the fruit fly Drosophila sechellia is adapted to the toxic fruits of the morinda tree. Drosophila sechellia females, which lay their eggs on these fruits, carry a mutation in a gene that inhibits egg production. The flies have very low levels of l-DOPA , a precursor of the hormone dopamine, which controls fertility; interestingly, large amounts of l-DOPA are contained in morinda fruits. Flies that were fed with l-DOPA can compensate for the genetic deficiency and considerably increase their reproductive success. The same gene mutation also contributes to the resistance that these flies have to the toxic acids produced in...